Browse Prior Art Database

Hermetic Disk File

IP.com Disclosure Number: IPCOM000104522D
Original Publication Date: 1993-Apr-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 1 page(s) / 39K

Publishing Venue

IBM

Related People

Guarnieri, CR: AUTHOR [+4]

Abstract

A hard disk memory file can be sealed inside a hermetic enclosure of non-contaminating environment using the apparatus in the figure.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Hermetic Disk File

      A hard disk memory file can be sealed inside a hermetic
enclosure of non-contaminating environment using the apparatus in the
figure.

      The valve on the disk package is opened and closed with the
hermetic rotary shaft RS.  The disk package is evacuated and
backfilled with nitrogen 90% and helium 10% gas.  During this
processing the gas flow must be kept at or below 20 standard cubic
centimeters per minute.  Higher gas flows will damage sensitive
components in the disk package.  The flow meter FM measures gas
throughput both at atmospheric pressure and under vacuum.  The
control valve CV with a large variable conductance uses the signal
from the flow meter FM to keep the gas throughput constant during
evacuation.  The conductance increases as the pressure decreases.
The flow controller FC with a built in servo valve is used for
backfilling the disk package with the appropriate nitrogen-helium
mixture.  This flow controller is being used in the conventional way
with the gas source slightly above atmospheric pressure.  Baking the
disk package to increase the outgassing rate, can be done either
prior to evacuation or during evacuation.  The pressure transducer P
is used to determine the final evacuation pressure and the backfill
pressure.  An oil free dry pump is used to prevent oil contamination.

Disclosed Anonymously.